The invention relates to power-driven conveyors generally and, more particularly, to modular conveyor belts with conveying surface platforms and the ability to flex sidewise to negotiate turns.
Because they do not corrode and are easy to clean, plastic conveyor belts are used widely, especially to convey food products. Modular plastic belts are constructed of molded plastic links, or belt modules, arranged in rows. Spaced-apart hinge elements, or link ends, extending from each end of the modules include aligned apertures to accommodate a pivot rod, or hinge pin. The hinge elements along one end of a row of modules are interleaved with the hinge elements of an adjacent row. A hinge pin journaled in the aligned apertures of the end-to-end rows, connects adjacent rows together to form an endless modular conveyor belt capable of articulating about a drive sprocket.
In many industrial applications, conveyor belts are used to carry products along paths including curved, as well as straight, segments. Belts capable of flexing sidewise to follow paths are referred to as side-flexing, turn, or radius belts. As a radius belt negotiates a turn, the edge of the belt at the outside of the turn follows a longer path than the edge at the inside of the turn. To enable the belt to negotiate the turn, the apertures in the hinge elements along at least one end of a row of modules are typically elongated in the direction of belt travel. The elongated apertures allow the belt to collapse at the inside of a turn. The spaces between adjacent hinge elements in radius belts are deep to accommodate the interleaved hinge elements of the adjacent row at the inside of a turn.
Because a belt under tension must collapse at the inside of a turn, radius belts are designed without structural features that would interfere with the collapsing of adjacent belt rows. For this reason, radius belts are typically open-area belts. Flat-top belts, which are characterized by a continuous, largely closed conveying surface, are typically straight-running belts only.
Thus, there is a need for a modular conveyor belt capable of following a curved path and providing a conveying surface that is largely continuous and closed.
This need and others are provided by a platform-top radius belt embodying features of the invention. Such a belt, in one version, is constructed of a series of rows of belt modules. Each row includes at least one belt module that extends from a first end to a second end in the direction of belt travel. A first plurality of hinge elements is disposed along the first end, and a second plurality along the second end. First aligned apertures are formed in the first plurality of hinge elements, and second aligned apertures are formed in the second plurality of hinge elements. Apertures through the first or second pluralities of hinge elements are elongated in the direction of belt travel. The first and second pluralities of hinge elements extend from intermediate structure of the belt modules. A product support platform is attached to the intermediate structure. The platform has a conveying surface. An extension of the conveying surface extends over a portion of the first plurality of hinge elements and forms a gap that separates the overhanging extension and the hinge elements. An edge portion extends from the product support platform opposite the overhanging extension. The edge portion is recessed below the level of the conveying surface. The first plurality of hinge elements along each row is interleaved with the second plurality of hinge elements of an adjacent row. The aligned apertures of the interleaved hinge elements form passageways between adjacent rows that receive hinge pins to pivotably connect adjacent rows together into a conveyor belt.
In another version of the belt, a product support platform has a generally continuous conveying surface that is elevated above upper surfaces of the first and second pluralities of hinge elements. A gap separates the product support platform and the upper surfaces of the first plurality of hinge elements.
In yet another version, a product support platform has a first edge overlying the first plurality of hinge elements and an opposite recessed second edge that extends onto the second plurality of hinge elements. The second edge is contoured to receive the first edge of an adjacent row.
In still another version, the conveying surface is generally rectangular. In another version, the first and second edges of the product support platform each follow a nonlinear edge pattern.
One version of a conveyor belt module embodying features of the invention includes a first plurality of hinge elements and a second plurality of hinge elements extending from intermediate structure toward opposite first and second ends of the module. A product support platform, attached to the intermediate structure, has a conveying surface that is elevated relative to the hinge elements. An overhang extends from the conveying surface above the first plurality of hinge elements across a gap.
In another version of a conveyor belt module, the conveying surface is generally rectangular. In still another version, the product support platform includes opposite first and second edges in a nonlinear edge pattern.
Thus, the invention provides a modular conveyor belt and modules for its construction that provide a conveying platform in a radius belt that can operate on straight and curved conveying paths.